Models of $VTC^0$ as exponential integer parts (2209.01197v2)

Abstract: We prove that (additive) ordered group reducts of nonstandard models of the bounded arithmetical theory $\mathsf{VTC^0}$ are recursively saturated in a rich language with predicates expressing the integers, rationals, and logarithmically bounded numbers. Combined with our previous results on the construction of the real exponential function on completions of models of $\mathsf{VTC^0}$, we show that every countable model of $\mathsf{VTC^0}$ is an exponential integer part of a real-closed exponential field.